Electric clock



.April 19, 1938. E. P. OSWALD ELECTRIC CLOCK Filed Feb. 13, 1937 2Sheets-Sheet 2 6224*! Q 405%??? ZZW/ w ORNEY.

Patented Apr. 1 9 1 938 UNITED STATES ELECTRIC CLOCK Earl P. Oswald,

Oak Park, Mich.

Application February 13, 1937, Serial No. 125,546

4' Claims.

This invention relates to clocks and in .par-

ticular to electric clocks of the cyclometer type- One object of thisinvention is to provide a synchronous motor operated cyclometer type.electricclock.

Another object of this invention is to provide a synchronous motoroperated cyclometer type electric clock having time indicating drumsmounted for progressive rotation on a common axis.

Another object of this invention is to provide a synchronous motoroperated cyclometer type electric clock having novel inexpensive meansfor progressively rotating the time indicating drums thereof.

Another object of this invention is to provide a synchronous motoroperated cyclometer type electric clock having minute, ten-minute andhour time indicating drums of equal face diameter 20 and mounted forprogressive rotation by novel inexpensive means on a common axis.

Another object of this invention is toprovide a synchronous motoroperated cyclometer type electric clock in which the usual complicatedclockwork is substantially eliminated.

Another object of this invention is to provide a synchronous motoroperated cyclometer type electric clock having such simple operatingmechanism as to readily fit in with high speed part production andassembly methods whereby the clock may be manufactured at a cost thatwill make it available to the low price field.

Other objects of the invention will become apparent by reference to thefollowing detailed 5 description taken in connection with theaccompanying drawings, in which:

Fig. l is a front elevational view of a clock mechanism embodying theinvention.

Fig. 2 is a side elevational view of the embodiment oi the clockmechanism disclosed in Fig. 1 showing the notching and numbering of theminute drum.

Fig. 3 is a horizontal sectional view taken on the line 3--3 of Fig. 1.

Figs. 4 and 5 are enlarged side elevational and plan views respectivelyof the novel drum engaging ratchet lever employed to selectively andprogressively rotate the time indicating drums.

Fig. 6 is a side eleva-tional view of the ten-minute drum. showing thenotching and numbering thereof.

Fig. 7 is a side elevational view of the hour drum showing the notchingand numbering thereof.

Fig. 8 is an enlarged composite more or less diagrammatic view showingthe position of all the drums just after they have been moved toindicate time at an even hour.

Fig. 9 is a view in perspective showing a typical back motion springpawl employed to prevent 5 any reverse rotation. of the time indicatingdrums.

Referring now to the drawings wherein like numerals refer to like andcorresponding parts throughout the several views, the embodiment of theinvention disclosed therein comprises, in general, a minute drum 2!], aten-minute drum 2| and an hour drum 22 mounted for rotation independentof each other on a common shaft 23, each. of said drums beingintermittently and progressively rotated by a reciprocating bifurcatedratchet lever 24 carrying a novel sliding ratchet click 25 which engagessuitably disposed ratchet teeth formed on the inner periphery of thesaid time indicating drums 20, 2| and 22, the said ratchet lever 24being reciprocated under the power and timing of a preferablyself-starting synchronous motor 26.

The clock mechanism is supported within a suitable housing indicated bythe dot and dash lines 21 in Figs. 1 and 2 on an inverted U-shapedbracket 28 through which the shaft 23 is centrally mounted throughshouldered bearings 29 peened into engagement with the said bracket 23.The minute drum 20, ten-minute drum 2| and hour drum 22 journaled on theshaft 23 are assembled on the shaft 23 positioned through the bearings29 as best shown in Fig. 3 with the reciprocating bifurcated ratchetlever 24 journaled for arcuate reciprocation on the outer periphery ofthe said bearings 29 and straddling 35 the ten-minute drum 2| and theU-shaped bracket 28. The said drums 20, 2| and 22 are maintained in thedesired position on the shaft 23 by such suitable means as split springclips 30 snapped over the said shaft 23 into annular 10 grooves providedin the said shaft 23 therefor.

The minute drum 20, the ten-minute drum 2| and the hour drum 22 are allof equal face diameter, the said minute drum 2!) being ten sided andnumbered from 0 to: 9 consecutively as indi- 45 cated in Fig. 2, whilethe ten-minute and hour drums are twelve sided and are numbered 0, 1, 2,3, 4, 5, 0, 1, 2, 3, 4, 5 and from 1 to 12 consecutively as indicated inFigs. 6 and 7 respectively. The numbering of the drums being all thesame height is exposed for view through a suitable aperture 3| in thehousing 21.

Each of the drums 20, 2| and 22 are formed hollow and are each supportedon an integral radially disposed disc 32 having a centrally dis- 55posed hub 33 by means of which they are journaled on the said shaft 23as hereinbefore described.

As best illustrated in Figs. 2, 3 and 8, the minute drum 20 isinternally formed on its side adjacent the ten-minute drum 2| into aratchet wheel having nine shallow teeth 34 and one deep tooth 35 equallyperipherally spaced and radially located. opposite the center of eachnumbered side of the said minute drum 29, said deep tooth 35 beinglocated radially opposite the side bearing the numeral 5.

As best illustrated in Figs. 3, 6 and 8, the tenminute drum 2| isinternally formed on its side adjacent the minute drum 20 into a ratchetwheel having ten shallow teeth 36 and two deep teeth 31 equallyperipherally spaced and radially located opposite the center of eachnumbered side of the said ten-minute drum 2|, the said deep teeth 31being each located radially opposite one of the two sides bearing thenumeral 0.

As best illustrated in Figs. 3, 7 and 8, the hour drum 22 is internallyformed on its side adjacent the ten-minute drum 2| into a ratchet wheelhaving twelve shallow teeth 38 equally peripherally spaced and radiallylocated opposite the center of each numbered side of the said hour drum22.

The radii from the center of the drums to the base of the notches formedby the deep tooth 35 of the minute drum 20, by the deep teeth 3'! of theten-minte drum 2| and by all the teeth 38 of the hour drum 22 are allequal and greater than the radius from the center of the said drums tothe base of any of the notches formed by any of the other teeth. Theradii from the center of the minute drum 2!] to the base of the notchesformed by the nine teeth 34 thereof are all equal and less than theradius from the center of any of the drums 20, 2| and 22 to any of theother teeth. The radii from the center of the ten-minute drum 2| to thebase of the notches formed by the ten teeth 36 thereof are all equal andof such length as to make the bases of the notches formed by the saidteeth 36 radially equidistant from the bases of the notches formed bythe tooth 35 of the minute drum, teeth 31 of the ten-minute drum, teeth38 of the hour drum and the bases of the notches formed by the teeth 34of the minute drum.

The teeth 34, 36 and 38 are all of an equal depth and of a dimensionslightly greater than the radius of the tooth engaging pins 250 of thesliding ratchet click 25 to admit of engagement thereby. The radialdistance between the bases of the notches formed by the teeth 34 and 36and the radial distance between the bases of the notches formed by theteeth 36 and 38 is slightly greater than the diameter of the said toothengaging pins 250 of the said sliding ratchet click 25 to admit ofselective engagement and progressive rotation of the drums 20, 2| and 22thereby.

A plurality of back motion spring pawls 39 formed as best illustrated inFig. 9 are positioned through preferably rectangular apertures 40 in theU-shaped bracket 28 in such a manner as to engage the internal ratchetwheels formed in the drums 20, 2| and 22, see Figs. 2 and 3.

Referring now to Figs. 2, 3, 4 and 5, the bifurcated ratchet lever 24 isprovided with apertures 4| by means of which the said ratchet lever 24is journaled for arcuate reciprocation around the bearings 29 which arecentered in respect to the center of the drums 20, 2| and 22 ashereinbefore described. A suitably disposed clip 42 is preferably formedintegral with the closed end of the bifurcated ratchet lever 24 and isprovided with an aperture 43 through which a pivot pin 44 is positionedfor pivotally securing the connecting lever 45 to the said bifurcatedratchet lever 24.

Arcuate reciprocation once each minute is imparted to the ratchet lever24 by means of a positive speed synchronous motor 26 having a worm 46 onthe rotating shaft 4'! thereof which engages the worm gear 48 androtates the same once each minute. The connecting lever 45 iseccentrically pivoted on the worm gear 48 by a pivot pin 49 as bestillustrated in Fig. 2. The dot and dash lines in Fig. 2 indicate theposition of the connecting lever 45 and the bifurcated ratchet lever 24at the limit of their return stroke, while the full and dotted lines inFig. 2 indicate the position of the connecting lever 45 and thebifurcated ratchet lever 24 at the completion of their drum rotatingstroke. The synchronous motor 26 preferably carries a suitable support58 onto which the worm gear 48 is journaled by such means as ashouldered rivet 5|, the said synchronous motor 26 being supported onand secured to the upper horizontal portion of the U-shaped bracket 28.

Referring now to Figs. 4 and 5, the bifurcated ratchet lever 24 iscrimped at 52 and is suitably slotted along the narrow sides 248 thereofto accommodate a bifurcated ratchet click 25 held in alignment with thenarrow sides 240 of the said ratchet lever 24 by the wide sides 24|thereof and by the end 242 thereof. An additional guide and pin 53around which a light compression spring 54 is positioned is riveted orotherwise secured protruding outward from the end 242 of the ratchetlever 24 and reciprocatingly extends through an aperture 55 providedtherefor through the end 25| of the said bifurcated ratchet click 25.The said bifurcated ratchet click 25 is provided with three pins 250suitably disposed to engage the internally formed ratchets of the timeindicating drums 20, 2| and 22. The said light compression spring 54reacts against the end 242 of the ratchet lever 24 and constantly urgesthe ratchet click 25 outward with the tooth engaging pins 250 thereof incontact with one or more of the internally formed ratchet wheels of thetime indicating drums 20, 2| and 22 as hereinafter described.

The mechanism of the clock being thus described makes the operation ofthe clock obvious. Beginning at any even hour, each time the ratchetlever 24 is reciprocated once, which occurs once each minute, one toothengaging pin 25!] engages one of the teeth 34 of the ratchet wheelformed within the minute drum 2B and advances the minute dial onenumeral. After this occurs nine times, one tooth engaging pin 25!!engages the tooth 35 of the minute drum 20 and another tooth engagingpin 250 engages one of the teeth 36 of the ten-minute drum 2| whereuponthe minute dial and the ten-minute dial simultaneously advance onenumeral to read ten minutes after the hour.

The aforementioned operation is repeated until the clock readsfifty-nine minutes after the hour and one of the tooth engaging pins 250engages the tooth 35 of the minute drum 20, another tooth engaging pin250 engages one of the teeth 31 of the ten-minute drum 2|, and the thirdtooth engaging pin 250 engages one of the teeth 38 of the hour drum 22at the limit of the return stroke of the ratchet lever 24 whereupon theratchet lever 24 carrying the ratchet click 25 and the tooth engagingpins 250 advances the minute dial 20, the ten-minute dial 2!, and thehour dial 22 simultaneously one numeral each under the drum rotatingstroke of the said ratchet lever 24 until the three tooth engaging pins250 and the drums 20, 2! and, 22 are in the position or a comparableposition to that indicated in Figs. 1, 2, 3 and 8, at which time an evenhour is recorded through the opening 3! of the clock housing 21.

It will be noted that the relative depth of the notches of the ratchetwheels internally formed in the minute drum 20, the ten-minute drum 2|and the hour drum 22 and the various lateral alignments thereof governswhether the tooth engaging pins 250 of the sliding ratchet click 25 ofthe reciprocating ratchet lever 24 move one or more of the said drums20, 2| and 22.

Although but one embodiment of the invention has been shown anddescribed herein, it will be understood that various changes may be madein the size, shape, arrangement and details of the various parts thereofwithout departing from the spirit of the invention, and it is notintended to limit the scope of the invention other than by the terms ofthe appended claims.

I claim:

1. An electric clock mechanism comprising a positive speed synchronousmotor, a minute, a ten minute and an hour time indicating drum, a commonshaft, the said drums being mounted on said common shaft for rotationindependent of each other, ratchet wheels formed on the inner peripheryof said drums having certain of the teeth thereof at different depthswith respect to the others, a ratchet lever mounted on said common shaftarcuately reciprocated once each minute by said synchronous motor, and asliding ratchet click on said ratchet lever constantly urged radiallyoutward into selective engagement with one or more of the said timeindicating drums in accordance with the lateral and radial alignment ofthe notches of the ratchet wheels formed in the said drums whereupon thesaid drums are progressively rotated by said ratchet lever.

2. An electric clock mechanism comprising a positive speed synchronousmotor, a minute, a ten minute and an hour time indicating drum all ofequal face diameter, a common shaft, the said drums being mounted onsaid common shaft for rotation independent of each other, ratchet wheelsformed on the inner periphery of said drums having certain of the teeththereof at different depths with respect to the others, a ratchet levermounted on said common shaft arcuately reciprocated once each minute bysaid synchronous motor, and a sliding ratchet click on said ratchetlever constantly urged radially outward into selective engagement withone or more of the said time indicating drums in accordance with thelateral and radial alignment of the notches of the ratchet wheels formedin the said drums whereupon the said drums are progressively rotated bysaid ratchet lever,

3. An electric clock mechanism comprising a positive speed synchronousmotor, a minute, a ten minute and an hour time indicating drum all ofequal face diameter, a common shaft, the said drums being mounted onsaid common shaft for rotation independent of each other, the peripheryof the minute drum bearing equally spaced numerals from 0 to 9inclusive, the periphery of the ten-minute drum bearing equally spacednumerals 0-1-2-3-4-5-0-1-2-3-4-5, and the hour drum bearing equallyspaced numerals from 1 to 12 inclusive, ratchet wheels formed on theinner periphery of said drums having certain of the teeth thereof atdifferent depths with respect to the others, a ratchet lever mounted onsaid common shaft arcuately reciprocated once each minute by saidsynchronous motor, and a sliding ratchet click on said ratchet leverconstantly urged radially outward into selective engagement with one ormore of the said time indicating drums in accordance with the lateraland radial alignment of the notches of the ratchet wheels formed in thesaid drums whereupon the said drums are progressively rotated by saidratchet lever.

4. An electric clock mechanism comprising a positive speed synchronousmotor, a minute, a ten minute and an hour time indicating drum all ofequal face diameter, a common shaft, the said drums being mounted onsaid common shaft for rotation independent of each other, the peripheryof the minute drum bearing equally spaced numerals from 0 to 9inclusive, the periphery of the ten-minute drum bearing equally spacednumerals 0-1-2-3-4-5-0-1-2-3-4-5, and the hour drum bearing equallyspaced numerals from 1 to 12 inclusive, ratchet wheels formed on theinner periphery of said drums having one ratchet tooth disposed radiallyopposite each numeral and certain of the said teeth at different depthswith respect to the others, a ratchet lever mounted on said common shaftarcuately reciprocated once each minute by said synchronous motor, and asliding ratchet click on said ratchet lever constantly urged radiallyoutward into selective engagement with one or more of the said timeindicating drums in accordance with the lateral and radial alignment ofthe notches of the ratchet wheels formed in the said drums whereupon thesaid drums are progressively rotated by said ratchet lever.

EARL P. OSWALD.

